U.S. patent number 8,220,725 [Application Number 12/482,139] was granted by the patent office on 2012-07-17 for universal dispensing system for air assisted extrusion of liquid filaments.
This patent grant is currently assigned to Nordson Corporation. Invention is credited to Charles A. Gressett, Jr., David E. Hardy, John M. Riney, Laurence B. Saidman, Paul Schmidt.
United States Patent |
8,220,725 |
Gressett, Jr. , et
al. |
July 17, 2012 |
Universal dispensing system for air assisted extrusion of liquid
filaments
Abstract
A system for dispensing liquid material with different
configurations of air assisted fiberization or filament movement
(e.g., meltblowing, controlled fiberization). In particular, front
access for mounting a selected nozzle only requires adjustment of
one lever and one fastener. Features of the lever and nozzle allow
assisted ejection of the nozzle, even when the nozzle has become
adhered to a die body through use. In addition, a nozzle mounting
surface of the die body provides a universal interface to the
various types of nozzles. An air cavity in the die body and air
troughs in selected types of nozzles balance and adjust air
flow.
Inventors: |
Gressett, Jr.; Charles A.
(Norcross, GA), Hardy; David E. (Duluth, GA), Riney; John
M. (Buford, GA), Saidman; Laurence B. (Duluth, GA),
Schmidt; Paul (Sugar Hill, GA) |
Assignee: |
Nordson Corporation (Westlake,
OH)
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Family
ID: |
27123871 |
Appl.
No.: |
12/482,139 |
Filed: |
June 10, 2009 |
Prior Publication Data
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Document
Identifier |
Publication Date |
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US 20090242591 A1 |
Oct 1, 2009 |
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Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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10713451 |
Nov 14, 2003 |
7559487 |
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09999244 |
Jan 13, 2004 |
6676038 |
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09814614 |
Sep 16, 2003 |
6619566 |
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Current U.S.
Class: |
239/296; 425/182;
239/600; 239/298; 239/549; 239/556; 239/390 |
Current CPC
Class: |
B05B
15/65 (20180201); B05C 5/027 (20130101); B05B
7/0861 (20130101); B05C 5/02 (20130101) |
Current International
Class: |
B05B
1/28 (20060101) |
Field of
Search: |
;239/1,296,298,390,548,549,552,556,558,567,568,583,600
;425/7,72.2,182,185,186 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
Other References
European Patent Office, European Search Report in EP Application
No. 09161590, Jul. 9, 2009. cited by other .
European Patent Office, European Search Report in EP Application
No. 09161589, Jun. 24, 2009. cited by other .
European Patent Office, Office Action in EP Application No.
09161589.8, Jan. 25, 2011. cited by other.
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Primary Examiner: Ganey; Steven J
Attorney, Agent or Firm: Wood, Herron & Evans,
L.L.P.
Parent Case Text
This application is a divisional of U.S. application Ser. No.
10/713,451, filed on Nov. 14, 2003 (now pending) which is a
divisional of U.S. application Ser. No. 09/999,244, filed on Oct.
31, 2001 (now U.S. Pat. No. 6,676,038) which is a
continuation-in-part of U.S. application Ser. No. 09/814,614, filed
on Mar. 22, 2001 (now U.S. Pat. No. 6,619,566), the disclosures of
which are hereby incorporated by reference herein in their
entirety.
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is related to the following commonly-owned U.S.
Design Pat. No. D456,427 and U.S. Design Pat. No. D457,538, the
disclosures of which are hereby incorporated by reference herein in
their entirety. This application is also related to commonly-owned
U.S. Design Pat. No. D460,092 and U.S. Design Pat. No. D461,483,
the disclosures of which are hereby incorporated by reference
herein in their entirety.
Claims
The invention claimed is:
1. A nozzle adapted to be coupled to a dispenser having a nozzle
mounting surface and a lever, said nozzle adapted to dispense a
filament of liquid assisted by pressurized process air and
comprising: a top side, a bottom side and first and second side
walls between said top and bottom sides, said top side including a
liquid inlet and a process air inlet and said bottom side including
a liquid discharge orifice in fluid communication with said liquid
inlet and a plurality of process air discharge passages in fluid
communication with said process air inlet; and said first side wall
including a tab adapted for contact with the lever when the nozzle
is being moved away from the mounting surface of the dispenser.
2. The nozzle of claim 1, wherein said second side wall includes a
second tab for registering said nozzle with the mounting surface of
the dispenser.
3. The nozzle of claim 1, wherein said bottom side further
comprises a plurality of liquid discharge orifices.
4. The nozzle of claim 1, wherein said plurality of process air
discharge passages and said liquid discharge orifice are adapted to
produce a swirling filament.
5. A nozzle adapted to be coupled to a dispenser having a nozzle
mounting surface and an ejection lever, said nozzle adapted to
dispense a filament of liquid assisted by pressurized process air
and comprising: a top side, a bottom side and a cam surface, said
top side including a liquid inlet and a process air inlet and said
bottom side including a liquid discharge orifice in fluid
communication with said liquid inlet and a plurality of process air
discharge passages in fluid communication with said process air
inlet; and said cam surface adapted for contact with the ejection
lever while the lever is moving downwardly against said cam surface
thereby moving the nozzle away from the nozzle mounting surface of
the dispenser.
6. The nozzle of claim 5, wherein said cam surface is oriented in
an upward direction.
7. An apparatus for dispensing a filament of liquid, comprising:
(a) a housing including (i) a liquid supply passage, and (ii) a
nozzle mounting surface, said liquid supply passage opening on said
nozzle mounting surface; (b) a nozzle having an inlet side and an
outlet side, said inlet side positioned adjacent said mounting
surface and said outlet side having at least one liquid discharge
orifice for dispensing the filament, said liquid discharge orifice
being in fluid communication with said liquid supply passage of
said housing; and (c) a nozzle ejecting device affixed to said
housing and movable from a first position to a second position,
said nozzle ejecting device contacting said nozzle while moving
from said first position toward said second position thereby moving
said nozzle away from said nozzle mounting surface.
8. An apparatus for dispensing a filament of liquid, comprising:
(a) a housing including (i) a liquid supply passage, and (ii) a
nozzle mounting surface, said liquid supply passage opening on said
nozzle mounting surface; (b) a nozzle having an inlet side and an
outlet side and a side wall located between said inlet and outlet
sides, said inlet side positioned adjacent said mounting surface
and said outlet side having at least one liquid discharge orifice
for dispensing the filament, said liquid discharge orifice being in
fluid communication with said liquid supply passage of said
housing; and (c) a nozzle clamping and ejecting lever affixed to
said housing and movable to: (i) a first position for clamping said
nozzle adjacent said mounting surface with said liquid discharge
orifice in fluid communication with said liquid supply passage, and
(ii) a second position, wherein said nozzle clamping and ejecting
lever contacts said nozzle while moving from said first position
toward said second position thereby moving said nozzle away from
said mounting surface.
9. The apparatus of claim 8, wherein said nozzle further includes a
tab extending from said side wall and said nozzle clamping and
ejecting lever further comprises a slot adapted to receive said tab
to align said nozzle in a desired location with said nozzle
mounting surface.
10. The apparatus of claim 9, wherein said nozzle clamping and
ejecting lever further comprises: a first clamping member
engageable with said nozzle, a second clamping member coupled to
said first clamping member and engageable with said nozzle, said
slot positioned between said first and second clamping members, and
an ejecting portion extending between said first and second
members, said ejecting portion engageable with said tab for moving
said nozzle away from said mounting surface.
11. The apparatus of claim 8, wherein said housing further
comprises a process air supply passage and said outlet side of said
nozzle having a plurality of process air discharge outlets
communicating with respective process air discharge passages, said
process air discharge outlets and said process air discharge
passages being in fluid communication with said process air supply
passage.
12. The apparatus of claim 11, wherein said liquid discharge
orifice, said plurality of process air discharge outlets and said
process air discharge passages are adapted to produce a swirling
filament.
13. The apparatus of claim 8 wherein said lever includes a
tightening and locking fastener adapted to be tightened and locked
against said housing to move said lever and lock said lever in a
clamped position against said nozzle.
14. A nozzle adapted to be coupled to a dispenser having a nozzle
mounting surface and a liquid supply passage and a process air
supply passage extending through the nozzle mounting surface, said
nozzle adapted to dispense a filament of liquid assisted by
pressurized process air, and the nozzle comprising: a top side, a
bottom side, and first and second side walls located between said
top and bottom sides, said top side including a liquid inlet and a
process air inlet and said bottom side including a liquid discharge
orifice in fluid communication with said liquid inlet and a
plurality of process air discharge passages in fluid communication
with said process air inlet; and said first side wall including a
tab adapted to register said nozzle with the mounting surface of
the dispenser such that the liquid supply passage and process air
supply passage respectively communicate with said liquid inlet and
said process air inlet.
15. A nozzle adapted to be coupled to a dispenser having a nozzle
mounting surface and a liquid supply passage and a process air
supply passage extending through the nozzle mounting surface, said
nozzle adapted to dispense a filament of liquid assisted by
pressurized process air, and the nozzle comprising: a top side, a
bottom side, and first and second side walls located between said
top and bottom sides, said top side including a liquid inlet and a
process air inlet and said bottom side including a liquid discharge
orifice in fluid communication with said liquid inlet and a
plurality of process air discharge passages in fluid communication
with said process air inlet; and said first side wall including a
tab adapted to act as a camming surface for moving the nozzle away
from the mounting surface of the dispenser.
16. An apparatus for dispensing a filament of liquid, comprising:
(a) a housing including (i) a liquid supply passage, and (ii) a
nozzle mounting surface, said liquid supply passage opening on said
nozzle mounting surface; (b) a nozzle having an inlet side and an
outlet side and first and second side walls located between said
inlet and outlet sides, said first side wall including a tab, said
inlet side positioned adjacent said mounting surface and said
outlet side including a liquid discharge orifice for dispensing the
filament, said liquid discharge orifice being in fluid
communication with said liquid supply passage of said housing; and
(c) a nozzle clamping and ejecting lever affixed to said housing
and movable to: (i) a first position for clamping said nozzle
adjacent said mounting surface with said liquid discharge orifice
in fluid communication with said liquid supply passage, and (ii) a
second position, wherein said nozzle clamping and ejecting lever
contacts said tab while moving from said first position toward said
second position thereby moving said nozzle away from said mounting
surface.
17. The apparatus of claim 16, wherein said housing further
comprises a process air supply passage and said nozzle having a
plurality of process air discharge passages, said process air
discharge passages being in fluid communication with said process
air supply passage.
18. The apparatus of claim 17, wherein said liquid discharge
orifice and said process air discharge passages are adapted to
produce a swirling filament.
19. The apparatus of claim 16 wherein said second side wall
includes a tab for registering said nozzle with said nozzle
mounting surface.
20. The apparatus of claim 16 wherein said lever includes a
tightening and locking fastener adapted to be tightened and locked
against said housing to move said lever and lock said lever in a
clamped position against said nozzle.
21. A nozzle adapted to be coupled to a dispenser having a nozzle
mounting surface and a lever, said nozzle adapted to dispense a
filament of liquid and comprising: a top side, a bottom side and
first and second side walls between said top and bottom sides, said
top side including a liquid inlet and said bottom side including a
liquid discharge orifice in fluid communication with said liquid
inlet; and said first side wall including a tab adapted for contact
with the lever when the nozzle is being moved away from the
mounting surface of the dispenser.
22. The nozzle of claim 21, wherein said second side wall includes
a second tab for registering the nozzle with the mounting surface
of the dispenser.
Description
FIELD OF THE INVENTION
The present invention generally relates to dispensing systems for
applying a liquid material and, more particularly, for dispensing a
filament or filaments of liquid, such as hot melt adhesive, on a
substrate.
BACKGROUND OF THE INVENTION
Various liquid dispensing systems use air assisted extrusion
nozzles to apply viscous material, such as thermoplastic material,
onto a moving substrate. Often times, these systems are used to
form nonwoven products. For example, meltblowing systems may be
used during the manufacture of products such as diapers, feminine
hygiene products and the like. In general, meltblowing systems
include a source of liquid thermoplastic material, a source of
pressurized process air, and a manifold for distributing the liquid
material and process air. A plurality of modules or dispensing
valves may be mounted to the manifold for receiving the liquid and
process air and dispensing an elongated filament of the liquid
material which is attenuated and drawn down by the air before being
randomly applied onto the substrate. In general, a meltblowing die
tip or nozzle includes a plurality of liquid discharge orifices
arranged in a row and a slot on each side of the row of liquid
discharge orifices for dispensing the air. Instead of slots, it is
also well known to use two rows of air discharge orifices parallel
to the row of liquid discharge orifices.
Controlled fiberization dispensing systems also use air assisted
extrusion nozzles. However, the pressurized process air in these
systems is used to swirl the extruded liquid filament. Conventional
swirl nozzles or die tips typically have a central liquid discharge
passage surrounded by a plurality of process air discharge
passages. The liquid discharge passage is centrally located on a
protrusion. A common configuration for the protrusion is conical or
frustoconical with the liquid discharge passage opening at the
apex. The process air discharge passages are typically disposed at
the base of the protrusion. The process air discharge passages are
usually arranged in a radially symmetric pattern about the central
liquid discharge passage. The process air discharge passages are
directed in a generally tangential manner relative to the liquid
discharge orifice and are all angled in a clockwise or
counterclockwise direction around the central liquid discharge
passage.
Another type of air assisted nozzle, referred to herein as a
bi-radial nozzle, includes a wedge-shaped member having a pair of
side surfaces converging to an apex. A liquid discharge passage
extends along an axis through the wedge-shaped member and through
the apex. The wedge-shaped member extends in a radially
asymmetrical manner around the liquid discharge passage. Four
process air discharge passages are positioned at the base of the
wedge-shaped member. At least one process air discharge passage is
positioned adjacent to each of the side surfaces and each of the
process air discharge passages is angled in a compound manner
generally toward the liquid discharge passage and offset from the
axis of the liquid discharge passage.
These and other types of air-assisted extrusion nozzles generally
require periodic maintenance due to accumulation of dust, hardened
liquid material, or other reasons. Each dispensing valve may have
to be unbolted from the manifold by unscrewing at least two bolts.
The nozzle is then removed from the dispensing valve and another
nozzle is mounted onto the valve. If necessary, the valve is
reattached to the manifold. Consequently, such repair can increase
the required shut down time for removal and replacement of valves
and nozzles. Removal of the entire dispensing valve with the
attached nozzle is generally a requirement when changing between
applications (e.g., meltblowing to controlled fiberization).
For these reasons, it is desirable to provide apparatus and methods
for quickly changing nozzles on a die assembly without encountering
various problems of prior liquid dispensing systems. It is also
desirable to provide for easier maintenance and replacement of
air-assisted extrusion nozzles.
SUMMARY OF THE INVENTION
Generally, the present invention provides an apparatus for
dispensing a filament of liquid which may or may not be assisted by
pressurized process air. The apparatus comprises a housing having a
liquid supply passage and a nozzle mounting surface which may be
disposed within a recess of the housing. A nozzle includes an inlet
side positioned adjacent the mounting surface and an outlet side
having at least one liquid discharge orifice and, optionally, a
plurality of process air discharge passages adjacent the liquid
discharge orifice. When properly mounted and aligned against the
mounting surface, the liquid discharge orifice and the process air
discharge air passages are respectively in fluid communication with
the liquid supply passage and the process air supply passage of the
housing, if applicable. In one aspect of the invention, a nozzle
ejecting lever is pivotally affixed to the housing and pivotally
moves from a first position to a second position. In the first
position, the nozzle may be mounted adjacent the mounting surface
as described above and, as the ejecting lever is moved to the
second position, the nozzle is pried away from the mounting
surface. This assists in removing nozzles which may be otherwise
adhered to the housing due to thermoplastic liquid or other
reasons.
In another aspect of the invention, a nozzle positioning lever is
pivotally affixed to the housing to move between first and second
positions. In the first position the positioning lever allows the
nozzle to be mounted in a sealing manner within the housing recess
and adjacent the mounting surface. In the second position the
positioning lever holds the nozzle in the recess with the process
air discharge passages in fluid communication with the process air
supply passage and with the liquid discharge orifice in fluid
communication with the liquid supply passage. In the preferred
embodiment, the positioning lever and the ejecting lever may be one
and the same with different portions of the lever performing the
position and ejecting functions.
In another aspect of the invention, a clamping lever is pivotally
affixed to the housing and operates in conjunction with cam
surfaces on the nozzle and the housing to clamp the nozzle within
the housing recess. In the preferred embodiment, the positioning
lever is used to first position the nozzle within the recess and
temporarily hold the nozzle within the recess. The clamping lever
is then used to fixedly secure the nozzle within the recess for the
duration of the dispensing operation. For nozzle replacement,
repair and other maintenance purposes, the clamping lever may be
loosened and the positioning and ejecting lever may be used to at
least partially remove the nozzle from the recess.
In another embodiment of the invention, a clamping and ejecting
lever is provided such that a single lever may be used to clamp and
lock a nozzle into place on the housing and also to eject the
nozzle from the housing and the nozzle mounting surface. This lever
may be pivotally attached to the housing such that one portion
thereof is formed with one or more cam surfaces which engage one or
more cam surfaces of the nozzle to clamp and lock the nozzle into
place on the housing. Another portion of the lever may be used when
the lever is rotated in an opposite direction to eject the nozzle.
Preferably, the nozzle and the housing each include mating portions
which align the nozzle with respect to the housing. In this
embodiment, these portions take the form of one or more tabs on the
nozzle and one or more aligned slots in the housing adjacent the
nozzle mounting surface. The ejecting portion of the lever may
engage the tab to provide the prying force necessary to eject the
nozzle.
In a further aspect of the invention, the dispensing valve may
include an upper air actuating portion having a diaphragm/piston
arrangement for opening and closing the valve. This diaphragm may
be housed in a chamber having upper and lower pressurized air
supply ports. The upper chamber, in this aspect, includes a further
port which may or may not be plugged. When plugged, pressurized air
in the upper chamber may be used to force the diaphragm and piston
assembly downward to close the valve. When the plug is removed, any
pressurized air introduced into this upper chamber is
immediately exhausted, and a spring return mechanism takes over as
the valve closing mechanism.
A plurality of nozzles are provided in a liquid dispensing system
in accordance with the invention, with each nozzle configured to
discharge a different filament pattern. For example, a first nozzle
may be configured to dispense meltblown filaments while a second
nozzle may be configured to dispense a swirl filament pattern. Each
of the nozzles is constructed to be received in the recess such
that the liquid discharge orifice or orifices of the nozzle and the
process air discharge passages are respectively in fluid
communication with the liquid supply passage and process air supply
passage of the housing. Each nozzle is symmetrically configured
such that the nozzle may be rotated 180.degree. and still be
mountable within the housing recess. In this regard, the nozzle
includes cam surfaces on opposite sidewall portions thereof which
can each interchangeably engage the cam surface of the clamping
lever or a cam surface formed on a wall of the recess.
Various advantages, objectives, and features of the invention will
become more readily apparent to those of ordinary skill in the art
upon review of the following detailed description of the preferred
embodiments, taken in conjunction with the accompanying
drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
The accompanying drawings illustrate embodiments of the invention,
together with a general description of the invention given above,
and the detailed description of the embodiments given below, serve
to explain the principles of the invention.
FIG. 1 is a cross-sectional view of a dispensing system configured
to hold different types of air assisted extrusion nozzles in
accordance with the principles of the present invention for
dispensing liquid filaments;
FIG. 1A is an enlarged cross-sectional view of a lower portion of
the dispensing valve shown in FIG. 1, illustrating a nozzle
assembly;
FIG. 2 is a partially disassembled view of the dispensing valve
including the nozzle shown in FIG. 1;
FIG. 3 is perspective side view of the lower portion of the
dispensing valve shown in FIG. 1;
FIG. 4A is a cross-sectional view of the lower portion of the
dispensing valve shown in FIG. 1, illustrating insertion of a
nozzle, assisted by the positioning and ejecting lever;
FIG. 4B is a cross-sectional view of the lower portion of the
dispensing valve shown in FIG. 1, illustrating the nozzle being
frictionally held by the positioning and ejecting lever;
FIG. 4C is a cross-sectional view of the lower portion of the
dispensing valve shown in FIG. 1, illustrating ejection of the
nozzle, assisted by the positioning and ejecting lever;
FIG. 5 is an enlarged cross-sectional view of a meltblowing nozzle
constructed according to the invention;
FIG. 6 is a cut-away elevated perspective view of a controlled
fiberization nozzle constructed according to the invention;
FIG. 7 is a bottom perspective view of the controlled fiberization
nozzle of FIG. 6;
FIG. 8 is a top view of the nozzle of FIGS. 6 and 7;
FIG. 9 is a bottom perspective view of the meltblowing nozzle of
FIG. 5;
FIG. 10 is a top view of the meltblowing nozzle of FIGS. 5 and
9;
FIG. 11 is a bottom perspective view of a bi-radial nozzle
constructed according to the invention;
FIG. 12 is a top view of the bi-radial nozzle of FIG. 11;
FIG. 13 is an exploded perspective view of an alternative
dispensing valve and nozzle in accordance with another embodiment
of the invention;
FIG. 14 is a partially fragmented cross sectional view of the
discharge portion of the assembled dispensing valve and nozzle
shown in FIG. 13;
FIG. 15 is a cross sectional view of the upper section of the
dispensing valve shown in FIG. 13;
FIG. 16 is a perspective view illustrating one alternative nozzle
useful with the dispensing valve of FIG. 13; and
FIG. 17 is another alternative nozzle useful with the dispensing
valve shown in FIG. 13.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
For purposes of this description, words of direction such as
"upward", "vertical", "horizontal", "right", "left" and the like
are applied in conjunction with the drawings for purposes of
clarity. As is well known, liquid dispensing devices may be
oriented in substantially any orientation, so these directional
words should not be used to imply any particular absolute
directions for an apparatus consistent with the invention.
For purposes of simplifying the description of the present
invention, the illustrative embodiment will hereinafter be
described in relation to certain types of nozzles for distribution
of thermoplastic liquid such as hot melt thermoplastic adhesives,
but those of ordinary skill in the art will readily appreciate
application of the present invention to dispensing of other
materials and use of other types of nozzles.
With reference to the figures, and to FIGS. 1 and 1A in particular,
a liquid dispensing system 10 for air assisted extrusion of liquid
filaments is depicted as including a dispensing valve or die module
12 and a manifold 14. It will be appreciated that one or more of
the die modules 12 may be mounted in side-by-side relationship to
the manifold 14 that distributes liquid material and pressurized
air to each of the die modules 12. Each dispensing valve or die
module 12 includes a pneumatic valve mechanism 16 in a housing 18.
The pneumatic valve mechanism 16 is in fluid communication with the
manifold 14 to receive the liquid material and to a liquid material
flow passage 20 in the housing 18. The valve may alternatively be
electrically actuated for controlling flow of the liquid material
through the dispensing valve 12. A detailed description of the
pneumatic valve mechanism 16 is provided in U.S. Pat. No.
6,056,155, entitled "Liquid Dispensing Device" and assigned to
Nordson Corporation, the assignee of this invention. The disclosure
of U.S. Pat. No. 6,056,155 is hereby incorporated herein by
reference in its entirety.
The housing 18 includes an air supply passage 22 adapted to receive
the pressurized air from the manifold 14 and two air flow passages
24, 26 that are parallel to and on each side of the liquid material
flow passage 20. The pair of air flow passages 24, 26 allows
mounting of different types of nozzles, but does result in
different air flow path distances from the air supply passage 22.
Thus, an annular air chamber 28 in the housing 18 is in fluid
communication with both the air supply passage 22 and the air flow
passages 24, 26 for balancing air flow. The different types of
nozzles 32a, 32b, 32c benefit from the even distribution of air
flow. In the illustrative embodiments, these different types of
nozzles 32a, 32b, 32c include meltblowing, controlled fiberization
(hereinafter "swirl") and nozzles currently manufactured and sold
under the trademark SUMMIT.TM. by Nordson Corporation, the assignee
of the present invention. The SUMMIT.TM. nozzles are hereinafter
referred to as bi-radial nozzles.
Portions of the dispensing valve 12 form a nozzle assembly 30 for
selectively and expeditiously mounting various types of air
assisted extrusion nozzles 32a to the housing 18. In particular,
the nozzle assembly 30 includes a clamping structure that allows
access for removing and installing a nozzle 32a to the dispensing
valve 12 from the front side opposite the manifold 14. The nozzle
32a is frictionally held in contact with a nozzle mounting surface
36 by the opposition of a fixed member or wall 38 of the housing 18
and a positioning lever 40, which creates a positioning and
temporary clamping force parallel to the nozzle mounting surface
36. The temporary support avoids prolonged manual holding of the
nozzle 32a, which beneficially reduces the amount of time that a
user must be in contact with the typically hot surface of the
dispensing valve 12 as well as making installation more convenient.
This frictional force from the positioning lever 40 advantageously
supports the nozzle 32a while a pivoting clamping lever 42 locks
the nozzle 32a to the nozzle mounting surface 36. In particular, a
socket head cap screw 44, is threaded inward against housing 18,
outwardly pivoting an upper portion 46 of the clamping lever 42
about a pivot pin 48, thereby pivoting a lower portion 50 of the
clamping lever 42 under the nozzle 32a. Specifically, a cam surface
52 of the lower portion 50 makes inward and upward contact to a
forward cam surface 54 of the nozzle 32a, with a rearward cam
surface 56 of the nozzle 32a similarly supported by a cam surface
58 of the fixed member or wall 38.
As will be described in further detail below, different types of
air assisted extrusion nozzles 32a, 32b, 32c may be selected for
mounting to the nozzle assembly 30. The air inputs 60, 62 and
liquid input 64 of each nozzle 32a, 32b, 32c are registered to be
in liquid communication respectively with the liquid material flow
passage 20 and air flow passages 24, 26 of the housing 18.
Pressurized process air flow is diffused by one or more air troughs
66 that provide a tortuous air flow path through nozzle 32a and
slow down the air flow velocity exiting process air discharge
passages 68.
With reference to FIG. 2, the dispensing valve 12 is shown with the
nozzle 32a and nozzle assembly 30 disassembled to illustrate
additional features. The positioning lever 40 and clamping lever 42
are pivotally affixed to the housing 18 with the same pivot pin 48.
The positioning lever 40 resides within a slot 72 in the clamping
lever 42 that allows the positioning lever 40 to pivot upward to an
ejection position when the pivoting lever is in an unlocked or
loosened state. The cap screw 44 is retained within a threaded hole
74 in the clamping lever 42 by a snap ring 76. An upper surface 78
of the nozzle 32a includes a symmetric pattern of air inlets 60, 62
and liquid inlet 64 so that the nozzle 32a may be inserted in one
of two orientations with one being 180 degrees rotated from the
other. The upper surface 78 also includes symmetrically placed
alignment recesses 86, 88 registered to receive an alignment pin 90
affixed to the nozzle mounting surface 36 (shown in FIGS. 1 and
1A), that assist in positioning the upper surface 78 relative to
the nozzle mounting surface 36.
With reference to FIG. 3, the nozzle assembly 30 is shown with a
bi-radial nozzle 32a mounted, as one type of air assisted
extrusion. A detailed description of the bi-radial nozzle 32a is
disclosed in co-pending U.S. Ser. No. 09/571,703, entitled "Module
And Nozzle For Dispensing Controlled Patterns Of Liquid Material"
and assigned to the common assignee, the disclosure of which is
hereby incorporated herein by reference in its entirety. Shown in
phantom, a meltblowing nozzle 32b and a swirl nozzle 32c are shaped
similarly to the bi-radial nozzle 32a to be alternatively received
in a recess 91 of the housing 18.
With reference to FIGS. 4A-4C, use of the positioning lever 40 to
assist in mounting and ejecting a nozzle 32a is illustrated with
the clamping lever 42 adjusted to the unlocked position by
outwardly adjusting the cap screw 44. Thus, with reference to FIG.
4A, the cam surface 52 of the clamping lever 42 does not impede an
uninstalled nozzle 32a moved upward into proximity to the nozzle
mounting surface 36, as depicted by the phantom lines. The rearward
alignment recess 86 in the nozzle has sufficient dimensions to
register to the alignment pin 90 with the nozzle shifted slightly
forward to clear the fixed member or wall 38 which provides a rear
boundary for recess 91. If the positioning lever 40 is in the
ejection position, further upward movement of the nozzle 32a will
bear upon a projection 92 of the positioning lever 40, pivoting the
positioning lever 40 to an engaged position depicted in FIG. 4B. In
particular, a cam surface 40a is brought into frictional contact
with the forward surface 41 of the nozzle 32a. This urges the
rearward cam surface 56 into engagement with cam surface 58 of the
fixed member or wall 38 thereby forcing nozzle 32a against the
nozzle mounting surface 36. This temporarily aligns and clamps
nozzle 32a within recess 91. At this point, the clamping lever 42
may be moved to the locked position by tightening fastener 44
(shown best in FIG. 1A) for the period of use of the dispensing
valve 12. This urges cam surface 52 against cam surface 54 thereby
urging nozzle 32a upwardly into a clamped, sealing engagement
against mounting surface 36.
With reference to FIG. 4C, when the nozzle 32a requires repair or
replacement with another nozzle, the clamping lever 42 is moved to
the unlocked position as depicted. Then the positioning lever 40 is
used as an ejection lever and is pivoted upward toward the ejection
position. As the positioning lever 40 pivots upward, the projection
92 bears downward upon an upper cam surface 55 of the nozzle 32a
for ejecting the nozzle 32a. A prying force thus applied by the
positioning lever 40 on the nozzle 32a overcomes adhesion of
accumulated liquid material during use.
FIGS. 5-12 illustrate the three illustrative types of air assisted
extrusion nozzles 32a, 32b, 32c adapted for being universally
mounted to the dispensing valve 12.
With reference to FIGS. 6-8, the controlled fiberization nozzle 32c
has a circular air trough 94 that encompasses a central liquid
input 96. Each of the air jets 98 receives pressurized air from the
two air flow passages 24, 26 of the housing 18 after being diffused
and slowed down in the circular air trough 94 so that none of the
air jets 98 directly receives the pressurized air. Consequently,
the air flow is more uniform for all air jets 98, as arrayed about
a liquid orifice 100 that receives liquid material from the central
liquid input 96.
With reference to FIGS. 5, 9 and 10, the meltblowing nozzle 32b
depicted in FIG. 2 is shown having a row of orifices 102 flanked by
rows of air jets 104. Balancing the air flow to these air jets 104
and providing consistent liquid flow to the orifices 102 is
provided as shown in FIG. 10. The upper surface 78 of the nozzle
32b includes a central elongate slot 106 for communicating the
liquid material from the liquid material flow passage 20 of the
housing 18 to the length of the row of orifices 102. Two elongate
air troughs 108, 110 diffuse and slow down the air flow from each
air flow passage 24, 26 respectively to the rows of air jets
104.
Similarly, with reference to FIGS. 11 and 12, the bi-radial nozzle
32a includes an elongate central slot 112 for providing liquid
material to a row of orifices 70 and two elongate air troughs 66 to
diffuse and slow down the air flow from each air flow passage 24,
26 respectively to the rows of air jets 68 nonradially positioned
about the orifices 70.
By virtue of the foregoing, and in addition to other advantages a
nozzle assembly 30 for a dispensing valve 12 of a liquid dispensing
system 10 is readily reconfigurable for various types of air
assisted extrusion nozzles 32a, 32b, 32c without having to
disassemble the dispensing valve 12 from the manifold 14 or having
to remove multiple fasteners.
FIG. 13 illustrates an alternative dispensing valve or die module
120 comprised of a valve body 122 which may be fastenable to a
suitable support, such as a liquid and air supply manifold (not
shown), by respective fasteners 124 which may be engaged with a
tool at the front side of valve body 122. In this drawing, the
internal valve mechanism has been deleted for clarity. A nozzle
assembly 130 at the lower end of valve body 122 includes a nozzle
132a and a clamping and ejecting assembly 134 which is pivotally
movable in the direction of arrow 136 about a pivot pin 138 affixed
to a lower part 140 of valve body 122. Specifically, assembly 134
includes a lever 142 having two clamping members 142a, 142b. As
will be discussed further below, this lever 142 may be used to
clamp nozzle 132a into place by tightening bolt 144 against a
surface 146 (FIG. 14) within a recess 148 of valve body 122. Nozzle
132a is insertable within a recess 152 of valve body 122. As with
the previous embodiment, suitable liquid and air supply passages
are provided in valve body 122 for communicating with like passages
in nozzle 132a. In this regard, a passage 154 is provided for
supplying liquid to nozzle 132a and passages 156 (two out of four
shown) may be provided for directing process air into nozzle 132a.
It will be understood by those of ordinary skill that passages 154
and 156 may take other forms and shapes, such as slot-like
shapes.
Referring to FIGS. 13 and 14, a cam surface 160 is formed in recess
152 and a mating cam surface 162 is formed on nozzle 132a. On an
opposite side, a cam surface 164 is formed on nozzle 132a and this
cam surface 164 engages with respective cam surfaces 166, 168 on
clamp members 142a, 142b. Tabs 170, 172 on opposite sides of nozzle
132a register within respective slots 173, 174 in lever 142 and
valve body 122. As shown in FIG. 14, in the assembled condition,
respective surfaces 176, 178 of nozzle 132a and recess 152 engage
such that liquid supply passage 154 communicates with liquid
discharge passage 180 and process air passages 156 communicate with
process air discharge passages 182 of nozzle 132a. Thus, liquid,
such as hot melt adhesive, and process air are discharged through a
portion 184 of nozzle 132a which may, as in this example, be a
nozzle portion for emitting a swirled bead of adhesive.
Alternatively, a nozzle for extruding a bead or filament of liquid
without the assistance of process air may be used.
In operation, nozzle 132a is inserted into recess 152 by loosening
bolt 144 to such an extent that lever 142 can partially rotate
counterclockwise as viewed in FIG. 14. This allows the insertion of
nozzle 132a with tabs 170, 172 traveling through respective slots
174, 173. Once nozzle 132a is situated within recess 152, bolt 144
is tightened against surface 146. This rotates lever clockwise and
urges cam surfaces 166, 168 against cam surface 164 and further
urges cam surfaces 160, 162 together to clamp respective nozzle and
housing mounting surfaces 176, 178 together. To eject nozzle 132a,
bolt 144 is loosened sufficiently to allow partial rotation of
lever 142 in a counterclockwise direction as viewed in FIG. 14.
This urges surface portion 142c of lever 142 against tab 172 to pry
surfaces 176, 178 away from each other and eject nozzle 132a.
FIG. 15 illustrates an upper actuating portion 200 of dispensing
valve 120 including a reciprocating piston assembly 202 having a
shaft or rod 204 and a piston or diaphragm member 206. A spring
return mechanism 210 bears against a top of the shaft or rod 204 to
hold the rod 204 and, therefore, the valve 120 in a normally closed
position. An air port 212 is provided for allowing pressurized air
to be introduced beneath the piston or diaphragm 206 to lift the
shaft or rod 204 and therefore open the valve 120. A second port
214 is provided to communicate with a chamber 216 above the piston
or diaphragm 206 to allow the introduction of pressurized air above
diaphragm 206 in an "air-over-air" arrangement. In accordance with
another aspect of the invention, another port 218 is provided in
valve body 122 communicating with the upper chamber 216. This port
218 may receive a threaded plug 220 as shown in FIG. 13. When the
threaded plug 220 is removed as shown in FIG. 15, any pressurized
air which is introduced through the upper supply port 214 is
immediately exhausted through this port 218. In this instance, only
the spring assembly 210 will provide the closing force for valve
120.
FIGS. 16 and 17 illustrate two additional alternative nozzles 132b,
132c which are interchangeable with nozzle 132a in dispensing valve
120. Nozzle 132b is a meltblowing nozzle having a plurality of
liquid discharge orifices 230 on a central crest or apex 232 and
two identical series of process air discharge passages 234 (only
one series shown) on opposite sides of this central crest 232, as
previously described. Two additional crests or apices 236, 238 are
positioned on opposite sides of the central crest 232 and extend to
a plane beyond a plane which contains the central crest 232. Thus,
when nozzle 132b is dropped or supported on its discharge side, the
two outer crests 236, 238 will directly support the nozzle and
protect the central crest 232 from damage which could adversely
affect the discharge of liquid from orifices 230. Nozzle 132b
further includes cam surfaces 240, 242 which preferably form part
of the outer crests having apices 236, 238. These cam surfaces 240,
242 operate as previously described with respect to cam surfaces
162, 164 of nozzle 132a. In addition, nozzle 132b includes tabs
244, 246 which operate identically to tabs 170, 172 described in
connection with nozzle 132a.
Nozzle 132c is a bi-radial nozzle design having a discharge portion
250 as previously described. Nozzle 132c further includes cam
surfaces 252, 254 which operate identically to cam surfaces 162,
164 and cam surfaces 240, 242 described above. A pair of tabs 256,
258 operate identically to tabs 170, 172 and tabs 244, 246 as
previously described.
While the present invention has been illustrated by a description
of various preferred embodiments and while these embodiments have
been described in some detail, it is not the intention of the
Applicants to restrict or in any way limit the scope of the
appended claims to such detail. Additional advantages and
modifications will readily appear to those skilled in the art. The
various features of the invention may be used alone or in numerous
combinations depending on the needs and preferences of the user.
This has been a description of the present invention, along with
the preferred methods of practicing the present invention as
currently known. However, the invention itself should only be
defined by the appended claims, wherein we claim:
* * * * *